An electronic cigarette, or e-cigarette, is an electronic device that simulates the act of tobacco smoking by producing an inhaled mist or aerosol bearing the physical sensation, appearance, and the flavor and nicotine of inhaled tobacco smoke, without the odor and health risks associated with tobacco cigarettes. An e-cigarette generally uses heat or ultrasonics to vaporize a propylene glycol- or glycerin-based liquid solution into an aerosol for inhalation.
E-cigarettes are portable, self-contained cylindrical devices the size of which depends upon battery capacity. E-cigarettes have been designed to resemble actual cigarettes, cigars or even pipes. Some e-cigarettes are reusable, with replaceable and refillable parts; others are disposable.
E-cigarettes share three essential components. A “cartridge” serves as a mouthpiece and usually doubles as a small reservoir that holds the liquid that is to be vaporized. An atomizer serves as the heating element responsible for vaporizing the liquid to provide the aerosol mist. A battery unit serves as a battery supply in portable e-cigarette models. Other electronic components necessary for e-cigarette operation are housed within the battery unit.
A “cartomizer” option is available for many e-cigarettes. The cartomizer replaces the separate cartridge and atomizer components with a single integrated component, hence the nomenclature “cartomizer.” The cartomizer is disposable, as opposed to stand-alone atomizers that are reusable and comparatively expensive.
The cartridge is a small, usually disposable plastic container, with openings on each end. One end is placed in the user's mouth; the other end attaches to the atomizer. The cartridge serves as both a liquid reservoir and mouthpiece, and as such, must allow the passage of liquid to the atomizer, as well as aerosol from the atomizer back to the user's mouth without allowing liquid into the mouth. This is usually accomplished using an absorbent sponge-like material placed in the cartridge to keep the liquid in place and which rests on a plastic barrier separating it from the mouthpiece opening. The mouthpiece casing is constructed with side channels that allow aerosol mist to pass from the atomizer, around the liquid reservoir, to the mouthpiece opening and, thus, into the user's mouth. When the liquid in the cartridge has been depleted, the user can usually chose between refilling it or replacing it with another pre-filled cartridge.
The atomizer is a heating element that is responsible for vaporizing the liquid solution. The atomizer typically includes a simple filament and metal mesh to draw the liquid solution in from the cartridge. The atomizer is positioned in the center of the three components. That is, the cartridge attaches to one end of the atomizer and the battery unit attaches to the other end of the atomizer. The atomizer's filament tends to lose efficiency over time due to a build-up of sediment, or burns out entirely, requiring replacement.
Most portable e-cigarette battery units contain a rechargeable lithium-ion battery. The housing for the battery and the electronic circuitry required for operation of the e-cigarette is usually the largest component of the e-cigarette. The battery unit typically contains an electronic airflow sensor so that activation of the e-cigarette is triggered by drawing breath through the device. A colored LED may also be included in the battery unit to announce activation of the e-cigarette.
The contents of the liquid solution used to produce aerosol mist in e-cigarettes vary widely, but their common aspects include water and flavorings (e.g., tobacco smoke) in a propylene glycol or glycerin base. Nicotine is also included in solutions intended to fulfill a nicotine replacement role, without the carcinogenic tar associated with tobacco smoke.
U.S. Pat. No. 7,832,410, which issued on Nov. 16, 2010, discloses an example of an electronic atomization cigarette. U.S. Pat. No. 7,832,410 is hereby incorporated by reference herein in its entirety to provide background information regarding the present invention.